The game is set in the Victorian Era in London. While people live their lives quite normally in the daytime, there has been talk of strange murders occurring at night, when the moon is full.
Dr. Ferdinand Social, a young psychologist with a knowledge of the occult has received strange warnings from the guardian spirits of his Ouija board. The spirits warn him of more horrors to come, unless the source of the evil is defeated. So Dr. Social travels to the home of fellow occult specialist Julia Arkham. Upon his arrival Dr. Social discovers that Miss Arkham has apparently been kidnapped.
Returning to his home, Dr. Social finds his good friend Jonathan Harker waiting with a note sent from Miss Arkham which tells him that: "The vampire has returned. He controls powerful forces. He must be stopped!"
So Dr. Social knows he is the one who must stop the killings and save Miss Arkham. Because he does not know where to start, he does what any intelligent person would do. Ask his Ouija board for assistance...
Master of Darkness is a 2D action game much like Castlevania. Dr. Social can use a primary and a secondary weapon to defeat the monsters he encounters. The secondary weapons, however, are gone after use. These can not be "filled up" again. Another difference to Castlevania is that you can not pick up your old weapon once you have found a new one. This means that you could end up getting a weaker weapon than you had before. You start the game with three lives. After you have used all of them you can continue the game, but you have to start at the beginning of the round. At this point you can also save and quit, meaning you can start again in the last round you have reached.
Primary weapons consist of:
- Daggers: This is the weapon Dr. Social starts with. It does 1 point of damage.
- Sabers: These do 2 points of damage and have a longer reach than daggers.
- Stakes: Also with a longer reach these weapons do 3 points of damage.
- Axes: Although they have a shorter reach than Sabers and Stakes the 4 point damage of axes can kill most monsters with one blow.
Secondary weapons consist of:
- Pistol: With a supply of 16 bullets.
- Bomb: To throw down at hard-to-reach enemies.
- Boomerang: Different from your usual boomerang, these can not be catched on the way back.
- Projectile: This does 4 points of damage to enemies.
Throughout the game you can also find different items. Some are only good for points, others have a impact on the game as well:
Bonus Globes: These magical globes increase your score. There are four different types:
- Pink: 300 points
- Grey: 500 points
- Red: 1,000 points
- Black: 1,600 points
Emerald: This item destroys all enemies on the screen and is worth 100 points.
Life potion: Restores 4 out of 8 life globes.
Dr. Social Voodoo Doll: These masks give Dr. Social an extra life.
Different from what you find in Castlevania games the stages in Master of Darkness are linear. You do not have to backtrack and once you enter a new stage you can not go back to a previous stage.
There are 5 levels in total:
- Round 1: Thames River
- Round 2: The House of Wax Dolls
- Round 3: Epitaph
- Round 4: Laboratory
- Round 5: In the Wake of Dracula